Procedure to sell the land if ownership documents with someone else

Sir, My grand father bought a property (Society Patta) of 5 acres in Ranga Reddy district, Telangana in an auction in 1986. The land was given by Nizam earlier to the farmers. My grandfather bought it on the name of his eldest daughter. My Grand father has 3 children, My father and his two younger sisters. But when entering in the revenue records the pattwari has written my grandfather's name, insisting that My grandfather bought the land and it should be on his name. Since then the land is on his name only. And my aunt has no name in anywhere in the records. The agreement is made on a white paper attesting old stamps and witnesses and the original copy is with her. The government is not registering those properties and not giving Pattas. And now My grandfather wants to sell the land. So, what is the legal procedure to follow to sell the land.